ldmain.c

来自「基于4个mips核的noc设计」· C语言 代码 · 共 1,328 行 · 第 1/3 页

    }

  END_PROGRESS (program_name);

  if (config.stats)
    {
#ifdef HAVE_SBRK
      char *lim = (char *) sbrk (0);
#endif
      long run_time = get_run_time () - start_time;

      fprintf (stderr, _("%s: total time in link: %ld.%06ld\n"),
	       program_name, run_time / 1000000, run_time % 1000000);
#ifdef HAVE_SBRK
      fprintf (stderr, _("%s: data size %ld\n"), program_name,
	       (long) (lim - (char *) &environ));
#endif
    }

  /* Prevent remove_output from doing anything, after a successful link.  */
  output_filename = NULL;

  xexit (0);
  return 0;
}

/* We need to find any explicitly given emulation in order to initialize the
   state that's needed by the lex&yacc argument parser (parse_args).  */

static char *
get_emulation (argc, argv)
     int argc;
     char **argv;
{
  char *emulation;
  int i;

  emulation = getenv (EMULATION_ENVIRON);
  if (emulation == NULL)
    emulation = DEFAULT_EMULATION;

  for (i = 1; i < argc; i++)
    {
      if (!strncmp (argv[i], "-m", 2))
	{
	  if (argv[i][2] == '\0')
	    {
	      /* -m EMUL */
	      if (i < argc - 1)
		{
		  emulation = argv[i + 1];
		  i++;
		}
	      else
		{
		  einfo (_("%P%F: missing argument to -m\n"));
		}
	    }
	  else if (strcmp (argv[i], "-mips1") == 0
		   || strcmp (argv[i], "-mips2") == 0
		   || strcmp (argv[i], "-mips3") == 0
		   || strcmp (argv[i], "-mips4") == 0)
	    {
	      /* FIXME: The arguments -mips1, -mips2 and -mips3 are
		 passed to the linker by some MIPS compilers.  They
		 generally tell the linker to use a slightly different
		 library path.  Perhaps someday these should be
		 implemented as emulations; until then, we just ignore
		 the arguments and hope that nobody ever creates
		 emulations named ips1, ips2 or ips3.  */
	    }
	  else if (strcmp (argv[i], "-m486") == 0)
	    {
	      /* FIXME: The argument -m486 is passed to the linker on
		 some Linux systems.  Hope that nobody creates an
		 emulation named 486.  */
	    }
	  else
	    {
	      /* -mEMUL */
	      emulation = &argv[i][2];
	    }
	}
    }

  return emulation;
}

/* If directory DIR contains an "ldscripts" subdirectory,
   add DIR to the library search path and return true,
   else return false.  */

static boolean
check_for_scripts_dir (dir)
     char *dir;
{
  size_t dirlen;
  char *buf;
  struct stat s;
  boolean res;

  dirlen = strlen (dir);
  /* sizeof counts the terminating NUL.  */
  buf = (char *) xmalloc (dirlen + sizeof ("/ldscripts"));
  sprintf (buf, "%s/ldscripts", dir);

  res = stat (buf, &s) == 0 && S_ISDIR (s.st_mode);
  free (buf);
  if (res)
    ldfile_add_library_path (dir, false);
  return res;
}

/* Set the default directory for finding script files.
   Libraries will be searched for here too, but that's ok.
   We look for the "ldscripts" directory in:

   SCRIPTDIR (passed from Makefile)
   the dir where this program is (for using it from the build tree)
   the dir where this program is/../lib (for installing the tool suite elsewhere) */

static void
set_scripts_dir ()
{
  char *end, *dir;
  size_t dirlen;

  if (check_for_scripts_dir (SCRIPTDIR))
    /* We've been installed normally.  */
    return;

  /* Look for "ldscripts" in the dir where our binary is.  */
  end = strrchr (program_name, '/');
#ifdef HAVE_DOS_BASED_FILE_SYSTEM
  {
    /* We could have \foo\bar, or /foo\bar.  */
    char *bslash = strrchr (program_name, '\\');
    if (end == NULL || (bslash != NULL && bslash > end))
      end = bslash;
  }
#endif

  if (end == NULL)
    {
      /* Don't look for ldscripts in the current directory.  There is
         too much potential for confusion.  */
      return;
    }

  dirlen = end - program_name;
  /* Make a copy of program_name in dir.
     Leave room for later "/../lib".  */
  dir = (char *) xmalloc (dirlen + 8);
  strncpy (dir, program_name, dirlen);
  dir[dirlen] = '\0';

  if (check_for_scripts_dir (dir))
    /* Don't free dir.  */
    return;

  /* Look for "ldscripts" in <the dir where our binary is>/../lib.  */
  strcpy (dir + dirlen, "/../lib");
  if (check_for_scripts_dir (dir))
    return;

  /* Well, we tried.  */
  free (dir);
}

void
add_ysym (name)
     const char *name;
{
  if (link_info.notice_hash == (struct bfd_hash_table *) NULL)
    {
      link_info.notice_hash = ((struct bfd_hash_table *)
			       xmalloc (sizeof (struct bfd_hash_table)));
      if (! bfd_hash_table_init_n (link_info.notice_hash,
				   bfd_hash_newfunc,
				   61))
	einfo (_("%P%F: bfd_hash_table_init failed: %E\n"));
    }

  if (bfd_hash_lookup (link_info.notice_hash, name, true, true)
      == (struct bfd_hash_entry *) NULL)
    einfo (_("%P%F: bfd_hash_lookup failed: %E\n"));
}

/* Record a symbol to be wrapped, from the --wrap option.  */

void
add_wrap (name)
     const char *name;
{
  if (link_info.wrap_hash == NULL)
    {
      link_info.wrap_hash = ((struct bfd_hash_table *)
			     xmalloc (sizeof (struct bfd_hash_table)));
      if (! bfd_hash_table_init_n (link_info.wrap_hash,
				   bfd_hash_newfunc,
				   61))
	einfo (_("%P%F: bfd_hash_table_init failed: %E\n"));
    }
  if (bfd_hash_lookup (link_info.wrap_hash, name, true, true) == NULL)
    einfo (_("%P%F: bfd_hash_lookup failed: %E\n"));
}

/* Handle the -retain-symbols-file option.  */

void
add_keepsyms_file (filename)
     const char *filename;
{
  FILE *file;
  char *buf;
  size_t bufsize;
  int c;

  if (link_info.strip == strip_some)
    einfo (_("%X%P: error: duplicate retain-symbols-file\n"));

  file = fopen (filename, "r");
  if (file == (FILE *) NULL)
    {
      bfd_set_error (bfd_error_system_call);
      einfo ("%X%P: %s: %E\n", filename);
      return;
    }

  link_info.keep_hash = ((struct bfd_hash_table *)
			 xmalloc (sizeof (struct bfd_hash_table)));
  if (! bfd_hash_table_init (link_info.keep_hash, bfd_hash_newfunc))
    einfo (_("%P%F: bfd_hash_table_init failed: %E\n"));

  bufsize = 100;
  buf = (char *) xmalloc (bufsize);

  c = getc (file);
  while (c != EOF)
    {
      while (isspace (c))
	c = getc (file);

      if (c != EOF)
	{
	  size_t len = 0;

	  while (! isspace (c) && c != EOF)
	    {
	      buf[len] = c;
	      ++len;
	      if (len >= bufsize)
		{
		  bufsize *= 2;
		  buf = xrealloc (buf, bufsize);
		}
	      c = getc (file);
	    }

	  buf[len] = '\0';

	  if (bfd_hash_lookup (link_info.keep_hash, buf, true, true)
	      == (struct bfd_hash_entry *) NULL)
	    einfo (_("%P%F: bfd_hash_lookup for insertion failed: %E\n"));
	}
    }

  if (link_info.strip != strip_none)
    einfo (_("%P: `-retain-symbols-file' overrides `-s' and `-S'\n"));

  link_info.strip = strip_some;
}

/* Callbacks from the BFD linker routines.  */

/* This is called when BFD has decided to include an archive member in
   a link.  */

static boolean
add_archive_element (info, abfd, name)
     struct bfd_link_info *info ATTRIBUTE_UNUSED;
     bfd *abfd;
     const char *name;
{
  lang_input_statement_type *input;

  input = ((lang_input_statement_type *)
	   xmalloc (sizeof (lang_input_statement_type)));
  input->filename = abfd->filename;
  input->local_sym_name = abfd->filename;
  input->the_bfd = abfd;
  input->asymbols = NULL;
  input->next = NULL;
  input->just_syms_flag = false;
  input->loaded = false;
  input->search_dirs_flag = false;

  /* FIXME: The following fields are not set: header.next,
     header.type, closed, passive_position, symbol_count,
     next_real_file, is_archive, target, real.  This bit of code is
     from the old decode_library_subfile function.  I don't know
     whether any of those fields matters.  */

  ldlang_add_file (input);

  if (config.map_file != (FILE *) NULL)
    {
      static boolean header_printed;
      struct bfd_link_hash_entry *h;
      bfd *from;
      int len;

      h = bfd_link_hash_lookup (link_info.hash, name, false, false, true);

      if (h == NULL)
	from = NULL;
      else
	{
	  switch (h->type)
	    {
	    default:
	      from = NULL;
	      break;

	    case bfd_link_hash_defined:
	    case bfd_link_hash_defweak:
	      from = h->u.def.section->owner;
	      break;

	    case bfd_link_hash_undefined:
	    case bfd_link_hash_undefweak:
	      from = h->u.undef.abfd;
	      break;

	    case bfd_link_hash_common:
	      from = h->u.c.p->section->owner;
	      break;
	    }
	}

      if (! header_printed)
	{
	  char buf[100];

	  sprintf (buf, "%-29s %s\n\n", _("Archive member included"),
		   _("because of file (symbol)"));
	  minfo ("%s", buf);
	  header_printed = true;
	}

      if (bfd_my_archive (abfd) == NULL)
	{
	  minfo ("%s", bfd_get_filename (abfd));
	  len = strlen (bfd_get_filename (abfd));
	}
      else
	{
	  minfo ("%s(%s)", bfd_get_filename (bfd_my_archive (abfd)),
		 bfd_get_filename (abfd));
	  len = (strlen (bfd_get_filename (bfd_my_archive (abfd)))
		 + strlen (bfd_get_filename (abfd))
		 + 2);
	}

      if (len >= 29)
	{
	  print_nl ();
	  len = 0;
	}
      while (len < 30)
	{
	  print_space ();
	  ++len;
	}

      if (from != NULL)
	minfo ("%B ", from);
      if (h != NULL)
	minfo ("(%T)\n", h->root.string);
      else
	minfo ("(%s)\n", name);
    }

  if (trace_files || trace_file_tries)
    info_msg ("%I\n", input);

  return true;
}

/* This is called when BFD has discovered a symbol which is defined
   multiple times.  */

static boolean
multiple_definition (info, name, obfd, osec, oval, nbfd, nsec, nval)
     struct bfd_link_info *info ATTRIBUTE_UNUSED;
     const char *name;
     bfd *obfd;
     asection *osec;
     bfd_vma oval;
     bfd *nbfd;
     asection *nsec;
     bfd_vma nval;
{
  /* If either section has the output_section field set to
     bfd_abs_section_ptr, it means that the section is being
     discarded, and this is not really a multiple definition at all.
     FIXME: It would be cleaner to somehow ignore symbols defined in
     sections which are being discarded.  */
  if ((osec->output_section != NULL
       && ! bfd_is_abs_section (osec)
       && bfd_is_abs_section (osec->output_section))
      || (nsec->output_section != NULL
	  && ! bfd_is_abs_section (nsec)
	  && bfd_is_abs_section (nsec->output_section)))
    return true;

  einfo (_("%X%C: multiple definition of `%T'\n"),
	 nbfd, nsec, nval, name);
  if (obfd != (bfd *) NULL)
    einfo (_("%D: first defined here\n"), obfd, osec, oval);

  if (command_line.relax)
    {
      einfo (_("%P: Disabling relaxation: it will not work with multiple definitions\n"));
      command_line.relax = 0;
    }

  return true;
}

/* This is called when there is a definition of a common symbol, or
   when a common symbol is found for a symbol that is already defined,
   or when two common symbols are found.  We only do something if
   -warn-common was used.  */

static boolean
multiple_common (info, name, obfd, otype, osize, nbfd, ntype, nsize)
     struct bfd_link_info *info ATTRIBUTE_UNUSED;
     const char *name;
     bfd *obfd;
     enum bfd_link_hash_type otype;
     bfd_vma osize;
     bfd *nbfd;